[116.14] A Keck Survey of the M31 Halo

At a distance of 760 kpc, M31 presents us with a unique
opportunity to the spatial structure, chemical enrichment
history, star formation history, and dynamical properties of
the stellar halo belonging to a second large spiral galaxy.
Recent imaging of M31 with HST has produced a surprise: a
substantial intermediate-age population in a single halo
field at a distance of 11 kpc from the galaxy's center. In
this poster, we present preliminary results from a
photometric and spectroscopic study -- using LRIS on the
Keck telescope -- of three, 40 sq. arcminute halo fields at
galactocentric distances of 27 kpc.